1. Field of the Invention
The present invention relates to the sterilization of ground meat. In particular, the present invention relates to the sterilization of ground meat using supercritical CO2.
2. Description of the Related Art
The meat manufacturing industry processes ground meat in a manner that is intended to reduce and eliminate the exposure of the food product to microbes so as to prevent contamination. However, current methods of sterilizing ground meat produces a product that is either too expensive, loses vital taste and texture characteristics, becomes unsightly or exposes the product to unwanted irradiation. While the federal government is of the opinion that exposing meat to radiation is a safe and effective way to kill E. coli and other pathogens, meat companies have been hesitant to use irradiation because of fears that it would make meat more expensive, change the taste and color, and provoke consumer opposition.
Recent outbreaks of E coli, Listeria and Salmonella serve as evidence of the dangerous health issues facing consumers as well as the high costs associated of recalls and lost product. Escherichia coli bacteria are commonly found in the lower digestive tract of humans and animals, and they are usually harmless. But one strain, E. coli 0157:H7, produces a toxin that can make people sick, typically after eating ground beef or produce that has been contaminated by cattle feces.
As part of its efforts to eradicate E. coli, the meat industry is experimenting with vaccines, antibiotics and feed additives that may reduce the level of E. coli 0157:H7 in cattle intestines. But so far, such vaccines, antibiotics and feed additives are not commercially available. To date, nearly all of the efforts to curb E. coli have focused on interventions at slaughterhouses and at grinding plants that produce a variety of meat products.
Hamburger meat, or ground beef, poses an elevated risk of illness because grinding can mix live E. coli bacteria throughout the meat, and consumers often undercook their hamburgers. Steaks pose less of a risk because any E. coli on the surface are likely to be killed during cooking.
In all, the beef industry says it spends upward of $350 million a year to keep harmful pathogens out of the meat it sells to the public. But even as expenditures keep rising, the industry appears to be losing ground.
The U.S. Department of Agriculture issued new guidelines in October 2007 urging the meat industry to adopt the latest technology to combat harmful forms of E. coli. But department officials acknowledge that short of irradiating the meat, there is no magic bullet to prevent E. coli contamination.
Thus, there is a need for economical, efficient and reliable methods for sterilizing ground meat as it is being processed without affecting the quality of the meat. The present invention achieves this goal by using supercritical CO2 during the processing of the meat.